This study will test the efficacy of an innovative, inexpensive, resource-efficient treatment for thirst -- one of the most pervasive, intense, unrecognized, and under-treated symptoms suffered by critically ill patients in Intensive Care Units (ICUs). The first aim of this single-blinded, randomized clinical trial is to test a non-pharmacologic intervention for thirst in ICU patients. The intervention is a combination therapy treatment (CTT) for thirst that includes the use of sterile water mouth sprays, sterile water swabs, and menthol-based lip and tongue moisturizer. The second aim of the study is to examine demographic, environmental, and health and illness factors that increase an ICU patient's risk profile for thirst. Aim #1 hypotheses: (1) Thirst intensity and distress will decrease significantly in ICU patients who receive a CTT for thirst compared to those who receive research team observation. (2) Subjective (e.g., dry mouth) and objective (e.g., cracked lips) thirst-related characteristics will decrease significantly in ICU patients who receive a CCT for thirst compared to those who receive research team observation. Aim #2 hypotheses: (1) A significant association will be found between presence of thirst and certain risk factors for thirst, e.g., serum osmolality, hydration status, and administration of certain medications, e.g., opioids. (2) A significant association will be found between the intensity of thirst and certain risk factors for thirst, e.g., serum osmolality, hydration status, and administration of certain medications, e.g., opioids.